scholarly journals Dissection of a Hypoxia-induced, Nitric Oxide–mediated Signaling Cascade

2009 ◽  
Vol 20 (18) ◽  
pp. 4083-4090 ◽  
Author(s):  
Pascale F. Dijkers ◽  
Patrick H. O'Farrell
Keyword(s):  
Nitric Oxide ◽  
Signal Transduction ◽  
Signaling Cascade ◽  
S2 Cells ◽  
Signal Transduction System ◽  
Signaling Systems ◽  
Calcium Dependent ◽  
Drosophila S2 Cells ◽  
Oxide Synthase ◽  
Multiple Signaling

Befitting oxygen's key role in life's processes, hypoxia engages multiple signaling systems that evoke pervasive adaptations. Using surrogate genetics in a powerful biological model, we dissect a poorly understood hypoxia-sensing and signal transduction system. Hypoxia triggers NO-dependent accumulation of cyclic GMP and translocation of cytoplasmic GFP-Relish (an NFκB/Rel transcription factor) to the nucleus in Drosophila S2 cells. An enzyme capable of eliminating NO interrupted signaling specifically when it was targeted to the mitochondria, arguing for a mitochondrial NO signal. Long pretreatment with an inhibitor of nitric oxide synthase (NOS), L-NAME, blocked signaling. However, addition shortly before hypoxia was without effect, suggesting that signaling is supported by the prior action of NOS and is independent of NOS action during hypoxia. We implicated the glutathione adduct, GSNO, as a signaling mediator by showing that overexpression of the cytoplasmic enzyme catalyzing its destruction, GSNOR, blocks signaling, whereas knockdown of this activity caused reporter translocation in the absence of hypoxia. In downstream steps, cGMP accumulated, and calcium-dependent signaling was subsequently activated via cGMP-dependent channels. These findings reveal the use of unconventional steps in an NO pathway involved in sensing hypoxia and initiating signaling.

Isoforms of Nitric Oxide Synthase and the Nitric Oxide-Cyclic Gmp Signal Transduction System

1993 ◽  
pp. 73-80 ◽  
Author(s):  
Ferid Murad ◽  
U. Förstermann ◽  
M. Nakane ◽  
J. Pollock ◽  
H. Schmidt ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Signal Transduction ◽  
Nitric Oxide Synthase ◽  
Cyclic Gmp ◽  
Signal Transduction System ◽  
Oxide Synthase

scholarly journals Melatonin and Microglia

2021 ◽  
Vol 22 (15) ◽  
pp. 8296
Author(s):  
Rüdiger Hardeland
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Signal Transduction ◽  
Endothelial Cells ◽  
Bacterial Infections ◽  
Melatonin Receptors ◽  
Sterile Inflammation ◽  
High Complexity ◽  
Anti Inflammatory ◽  
Multiple Signaling

Melatonin interacts in multiple ways with microglia, both directly and, via routes of crosstalk with astrocytes and neurons, indirectly. These effects of melatonin are of relevance in terms of antioxidative protection, not only concerning free-radical detoxification, but also in prevention of processes that cause, promote, or propagate oxidative stress and neurodegeneration, such as overexcitation, toxicological insults, viral and bacterial infections, and sterile inflammation of different grades. The immunological interplay in the CNS, with microglia playing a central role, is of high complexity and includes signaling toward endothelial cells and other leukocytes by cytokines, chemokines, nitric oxide, and eikosanoids. Melatonin interferes with these processes in multiple signaling routes and steps. In addition to canonical signal transduction by MT1 and MT2 melatonin receptors, secondary and tertiary signaling is of relevance and has to be considered, e.g., via the upregulation of sirtuins and the modulation of pro- and anti-inflammatory microRNAs. Many details concerning the modulation of macrophage functionality by melatonin are obviously also applicable to microglial cells. Of particular interest is the polarization toward M2 subtypes instead of M1, i.e., in favor of being anti-inflammatory at the expense of proinflammatory activities, which is well-documented in macrophages but also applies to microglia.

Calcium regulates estrogen increase in permeability of cultured CaSki epithelium by eNOS-dependent mechanism

2000 ◽  
Vol 279 (5) ◽  
pp. C1495-C1505 ◽  
Author(s):  
George I. Gorodeski
Keyword(s):  
Nitric Oxide ◽  
Endothelial Nitric Oxide Synthase ◽  
Cytosolic Calcium ◽  
No Synthase ◽  
Calcium Dependent ◽  
Steady State Levels ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Dependent Mechanism

Estrogen increases baseline transepithelial permeability across CaSki cultures and augments the increase in permeability in response to hypertonic gradients. In estrogen-treated cells, lowering cytosolic calcium abrogated the hypertonicity-induced augmented increase in permeability and decreased baseline permeability to a greater degree than in estrogen-deprived cells. Steady-state levels of cytosolic calcium in estrogen-deprived cells were higher than in estrogen-treated cells. Increases in extracellular calcium increased cytosolic calcium more in estrogen-deprived cells than in estrogen-treated cells. However, in estrogen-treated cells, increasing cytosolic calcium was associated with greater increases in permeability in response to hypertonic gradients than in estrogen-deprived cells. Lowering cytosolic calcium blocked the estrogen-induced increase in nitric oxide (NO) release and in the in vitro conversion of l-[3H]arginine to l-[3H]citrulline. Treatment with estrogen upregulated mRNA of the NO synthase isoform endothelial nitric oxide synthase (eNOS). These results indicate that cytosolic calcium mediates the responses to estrogen and suggest that the estrogen increase in permeability and the augmented increase in permeability in response to hypertonicity involve an increase in NO synthesis by upregulation of the calcium-dependent eNOS.

scholarly journals Free radicals and the pancreatic acinar cells: role in physiology and pathology

2005 ◽  
Vol 360 (1464) ◽  
pp. 2273-2284 ◽  
Author(s):  
M Chvanov ◽  
O.H Petersen ◽  
A Tepikin
Keyword(s):  
Nitric Oxide ◽  
Signal Transduction ◽  
Acute Pancreatitis ◽  
Vascular Endothelium ◽  
Cell Injury ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Nitrogen Species ◽  
Key Enzyme ◽  
Oxide Synthase

Reactive oxygen and nitrogen species (ROS and RNS) play an important role in signal transduction and cell injury processes. Nitric oxide synthase (NOS)—the key enzyme producing nitric oxide (NO)—is found in neuronal structures, vascular endothelium and, possibly, in acinar and ductal epithelial cells in the pancreas. NO is known to regulate cell homeostasis, and its effects on the acinar cells are reviewed here. ROS are implicated in the early events within the acinar cells, leading to the development of acute pancreatitis. The available data on ROS/RNS involvement in the apoptotic and necrotic death of pancreatic acinar cells will be discussed.

scholarly journals Resting Tension Affects eNOS Activity in a Calcium-Dependent Way in Airways

2007 ◽  
Vol 2007 ◽  
pp. 1-6 ◽  
Author(s):  
Eudoxia Kitsiopoulou ◽  
Apostolia A. Hatziefthimiou ◽  
Konstantinos I. Gourgoulianis ◽  
Paschalis-Adam Molyvdas
Keyword(s):  
Nitric Oxide ◽  
Smooth Muscle ◽  
Calcium Concentration ◽  
Kinase Inhibitors ◽  
Calcium Dependent ◽  
Enos Activity ◽  
Resting Tension ◽  
Smooth Muscle Contractions ◽  
Oxide Synthase ◽  
Inducible Nos

The alteration of resting tension (RT) from 0.5 g to 2.5 g increased significantly airway smooth muscle contractions induced by acetylcholine (ACh) in rabbit trachea. The decrease in extracellular calcium concentration[Ca2+]ofrom 2 mM to 0.2 mM reduced ACh-induced contractions only at 2.5 g RT with no effect at 0.5 g RT. The nonselective inhibitor of nitric oxide synthase (NOS),NG-nitro-L-arginine methyl ester (L-NAME) increased ACh-induced contractions at 2.5 g RT. The inhibitor of inducible NOS, S-methylsothiourea or neuronal NOS, 7-nitroindazole had no effect. At 2.5 g RT, the reduction of[Ca2+]ofrom 2 mM to 0.2 mM abolished the effect of L-NAME on ACh-induced contractions. The NO precursor L-arginine or the tyrosine kinase inhibitors erbstatin A and genistein had no effect on ACh-induced contractions obtained at 2.5 g RT. Our results suggest that in airways, RT affects ACh-induced contractions by modulating the activity of epithelial NOS in a calcium-dependent, tyrosine-phosphorylation-independent way.

Inhibition of calcium-dependent nitric oxide synthase causes ileitis and leukocytosis in guinea pigs

1994 ◽  
Vol 39 (6) ◽  
pp. 1185-1192 ◽  
Author(s):  
Mark J. S. Miller ◽  
Upender K. Munshi ◽  
Halina Sadowska-Krowicka ◽  
Jane L. Kakkis ◽  
Xiao-Jing Zhang ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Guinea Pigs ◽  
Calcium Dependent ◽  
Oxide Synthase

scholarly journals Prolonged uterine artery nitric oxide synthase inhibition modestly alters basal uteroplacental vasodilation in the last third of ovine pregnancy

2014 ◽  
Vol 307 (8) ◽  
pp. H1196-H1203 ◽  
Author(s):  
Charles R. Rosenfeld ◽  
Timothy Roy
Keyword(s):  
Nitric Oxide ◽  
Uterine Artery ◽  
No Synthase ◽  
Uterine Horn ◽  
Signaling Systems ◽  
Uteroplacental Blood Flow ◽  
Dose Responses ◽  
Oxide Synthase ◽  
Cgmp Synthesis ◽  
In Pregnancy

Mechanisms regulating uteroplacental blood flow (UPBF) in pregnancy remain unclear, but they likely involve several integrated signaling systems. Endothelium-derived nitric oxide (NO) is considered an important contributor, but the extent of its involvement is unclear. Bolus intra-arterial infusions of nitro-l-arginine methyl ester (l-NAME) modestly decrease ovine basal UPBF; however, the doses and duration of infusion may have been insufficient. We, therefore, examined prolonged uterine artery (UA) NO synthase inhibition with l-NAME throughout the last third of ovine pregnancy by performing either continuous 30-min UA infusion dose responses ( n = 4) or 72-h UA infusions (0.01 mg/ml) at 104–108, 118–125, and 131–137 days of gestation ( n = 7) while monitoring mean arterial pressure (MAP), heart rate (HR), and UPBF. Uteroplacental vascular resistance (UPVR) was calculated, and uterine cGMP synthesis was measured. Thirty-minute UA l-NAME infusions did not dose dependently decrease UPBF, increase UPVR, or decrease uterine cGMP synthesis ( P > 0.1); however, MAP rose and HR fell modestly. Prolonged continuous 72-h UA l-NAME infusions decreased UPBF ∼32%, increased UPVR ∼68% ( P ≤ 0.001), and decreased uterine cGMP synthesis 70% at 54–72 h ( P ≤ 0.004); the noninfused uterine horn was unaffected. These findings were associated with ∼10% increases in MAP and decreases in HR that were greater at 104–108 than 118–125 and 131–137 days of gestation ( P = 0.006). Although uterine and UA NO and cGMP synthesis increase severalfold during ovine pregnancy, they contribute modestly to the maintenance and rise in UPBF in the last third of gestation. Thus, local UA NO may primarily modulate vasoconstrictor responses. Notably, the systemic vasculature appears more sensitive than the uterine vasculature to NO synthase inhibition.

Effect of Triterpene Acids of Eriobotrya japonica (Thunb.) Lindl. Leaf and MAPK Signal Transduction Pathway on Inducible Nitric Oxide Synthase Expression in Alveolar Macrophage of Chronic Bronchitis Rats

2009 ◽  
Vol 37 (06) ◽  
pp. 1099-1111 ◽  
Author(s):  
Y. Huang ◽  
J. Li ◽  
X. M. Meng ◽  
G. L. Jiang ◽  
H. Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Signal Transduction ◽  
Nitric Oxide Synthase ◽  
Alveolar Macrophage ◽  
P38 Mapk ◽  
Inducible Nitric Oxide Synthase ◽  
Inos Expression ◽  
Eriobotrya Japonica ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

The goal of this study was to investigate the possible therapy mechanism of triterpene acids of Eriobotrya japonica (Thunb.) Lindl. Leaf (TAL) in alveolar macrophage (AM) of chronic bronchitis (CB) rats. CB model was established by injection of bacillus calmette guein (BCG) plus lipopolisacharide (LPS) in rats. TAL significantly inhibited the increased NO concentration, iNOS expression and phosphorylation of p38 MAPK in alveolar macrophages (AMs) of CB rats. Using in vivo test, we found that SB203580, a p38 MAPK inhibitor, (10 μM) significantly inhibited inducible nitric oxide synthase (iNOS) mRNA expression in AM. This data indicate that TAL highly decreases excessive iNOS expression and NO induction, and p38 MAPK signal transduction participates in iNOS expression and NO induction in AM of CB rats. The effect of TAL on iNOS expression in AM may be related to its inhibition of p38 MAPK signal transduction.

scholarly journals Induction of nitric oxide synthase and heme oxygenase activities by endotoxin in the rat adrenal cortex: involvement of both signaling systems in the modulation of ACTH-dependent steroid production

2007 ◽  
Vol 194 (1) ◽  
pp. 11-20 ◽  
Author(s):  
N Grion ◽  
E M Repetto ◽  
Y Pomeraniec ◽  
C Martinez Calejman ◽  
F Astort ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Heme Oxygenase ◽  
Lethal Dose ◽  
Activity Levels ◽  
Steroid Production ◽  
Signaling Systems ◽  
Adrenal Response ◽  
Oxide Synthase

The present study was designed to investigate the effect of lipopolysaccharide (LPS) on the expression levels and activities of the nitric oxide synthase (NOS) and heme oxygenase (HO) systems in the rat adrenal gland. Both enzymatic activities were significantly increased in this tissue after in vivo treatment with LPS. The concurrent induction of the HO-1, NOS-1, and NOS-2 gene products was also detected as both mRNAs and protein levels were augmented by this treatment in a time-dependent way. A significant interaction between both signaling systems was also demonstrated as in vivo blockage of NOS activity with N(G)-nitro-L-arginine methyl ester (L-NAME) resulted in a significant reduction in HO expression and activity levels, while an increase in NOS activity was observed when HO was inhibited by Sn-protoporphyrin IX (Sn-PPIX). As both NOS and HO activities have been previously involved in the modulation of adrenal steroidogenesis, we investigated the participation of these signaling systems in the adrenal response to LPS. Our results showed that acute stimulation of steroid production by ACTH was significantly increased when either NOS or HO activities were inhibited. We conclude that adrenal NOS and HO can be induced by a non-lethal dose of endotoxin supporting a modulatory role for these activities in the adrenal response to immune challenges.

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